Electrical connector having improved contact retention means



Nov. 5, 1968 LYNCH ET AL ELECTRICAL CONNECTOR HAVING IMPROVED CONTACT RETENTION MEANS Filed Sept. 8, 1966 United States Patent C F 3,409,862 ELECTRICAL CONNECTOR HAVING IMPROVED CONTACT RETENTION MEANS James E. Lynch, Harrisburg, and Ronald C. Morehart, York aven, Pa., assignors to AMP Incorporated, Harrisburg, Pa.

Filed Sept. 8, 1966, Ser. No. 577,892 Claims. (Cl. 339196) ABSTRACT OF THE DISCLOSURE Electrical connector comprises housing having elongated slot extending for full length thereof on one side. A plurality of transverse slots extend inwardly on the one side and a side adjacent to the one side. Transverse slots intersect axially extending slot and contact terminals are mounted in these transverse slots. A retaining member of compressible insulating material is force fitted in the axially extending slot to retain the contacts in the housing.

Background of the invention This invention relates to rnulticontact electrical connectors of the type comprising an insulating housing having a plurality of electrical contact terminals therein. The invention is herein disclosed in an embodiment comprising a connector for printed circuit boards, however, it will be apparent that the principles of the invention can be utilized in other types of rnulticontact electrical connectors.

The methods of retaining contact terminals in electrical connector housings have become increasingly important because of the fact that such connectors are being used in increasing numbers and, in many circumstances, at least, must be produced at a relatively low cost. The instant invention is directed to the general problem of mounting a plurality of contact terminals in a connector block in an inexpensive and simple manner without sacrifice of the dimensional accuracy and precision which are required in such connectors.

It is an object of the invention to provide an improved arrangement for mounting contact terminals in an electrical connector block. A further object is to provide a mounting method which can be used with flat plate-like contact terminals which do not have retention means, such as retaining lances, thereon. A further object is to pro vide a method of mounting terminals in blocks which is amenable to automatic machine assembly methods.

These and other objects of the invention are achieved in a preferred embodiment in which the connector comprises an insulating housing having an axially extending slot on one side thereof. A plurality of transverse slots, which function as contact cavities, extend inwardly on this one side and on a side adjacent to the one side and intersect the axially extending slot. The contact terminals are mounted temporarily on a retaining member which comprises an elongated strip of insulating material having a cross-section such that it will fit in the axial slot of the connector block. The contacts may be temporarily secured to this retaining member by any suitable means, for example, by providing a projection or ear having a sharpened edge on the contacts which will bite into the surface of the retaining member. At the time of assembly, the contacts are mounted on the retaining member with their planes extending transversely of the axis thereof and the retaining member is thereafter force-fitted in the axial slot of the connector block. At this time, the contact terminals will be inserted into the transverse slots of the connector block and will be retained therein by the retaining member by virtue of its force-fit in the axial slot of the housing.

3,409,862 Patented Nov. 5, 1968 ice In the drawings:

FIGURE 1 is a perspective view of a connector housing in accordance with the invention mounted on a printed circuit board;

FIGURE 2 is a partially exploded view, similar to FIG- URE 1, showing the housing exploded from the board and the contact terminals exploded from the housing;

FIGURE 3 is a view taken along the lines 3-3 of FIGURE 1; and

FIGURES 4 and 5 are plan views of two types of contact terminals which are used in the embodiment shown in FIGURE 1.

The emobdiment of the invention disclosed herein is of a type, commonly referred to as a header, which is used to make disengageable connections between the conductors on a printed circuit board 10 and other conductors external to the board. The connector 2 comprises an elongated insulating block 4 having a plurality of contacts 6, 8 mounted therein in spaced-apart, side-by-side relationship. The contacts 6 (FIGURE 4) each comprise a fiat body portion 12 having a first contact arm 14 extending on one side thereof and having a pair of contact arms 16, 18 extending from an adjacent side. The arms 16, 18 are adapted to pass through holes in the printed circuit board 10 and to be electrically connected to conductors on the board as by soldering. The arm 14 is adapted to mate with a complementary contact in a connector block (not shown) which is complementary to the block 4. A relatively deep notch 20 extends inwardly on the edge of the contact between the arms 16, 18 and a portion 22 of the side of this notch is flattened and coined to form a penetrating edge capable of cutting into an insulating carrier bar 3.0 described below.

The contact 8 is similar in many respects to the contact 6 and its parts are identified by the same reference numerals, dilferentiated by prime marks, as those used for the contact 6. It will be noted that the arm 14 of the contact 8 is offset from the arm 14 of the contact 6 and the arms 16', 18' are also offset from their counterpart arms 16, 18 of the contact 6. The notch 20' of the contact 8 is located at the same distance from the rearward edge 24 as the notch 20 of the contact 6 for reasons which will become apparent as this description proceeds.

The block 4 has an axial slot 26 extending inwardly from its underside 32 and a plurality of transversely extending slots 28 which function as contact receiving cavities. The slots 28 extend inwardly from a side 34 adjacent to the underside 32 and from the underside 32. These slots intersect, and extend beyond the axially extending slot 26 and conform generally to the body portions 12, 12' of the contact terminals as shown in FIGURE 3.

When the block 4 is to be loaded with contact terminals 6, 8, the terminals are first mounted on a plastic carrier bar 30 in straddling relationship thereto. This carrier has a cross-section conforming to the cross-section of the axial slot and to the notches 20, 20 of the contacts. The contacts are spaced-apart by a distance equal to the center-tocenter spacing between adjacent cavities 28 of the block 4 so that when the carrier bar is inserted into the axial slot 26, the individual contacts will be moved into the cavities 28. The assembly of the contacts to the carrier bar can be carried out with the aide of a suitable jig and/ or a suitable assembling machine.

The housing block 4 is preferably of a relatively hard insulating material such as a diallyl phthalate or a filled epoxy resin. The carrier bar 30 is advantageously of a somewhat softer material, for example, a polypropylene, which will be relatively easily penetrated by the projections 22, 22' which function to retain the contacts on the carrier bar. The dimensions of the carrier bar are advantageously such that it must be forced into the axially extending slot 26 but after being thus forced into the slot,

it will remain in position by virtue of its internal compression. Alternatively, this carrier bar can be of a firm material and the contacts can be secured thereto by an adhesive, if desired.

After the contacts and the carrier bar have been assembled to the housing 2, the housing is positioned on the board with the arms 16, 18, 16, 18' extending through openings in the board. The portions of the arms which project beyond the underside of the board are then staked to the board and/or soldered to conductors on the board.

A salient advantage of the invention is that it is not necessary to provide any retaining means on the contacts themselves other than the sharpened edge projections 22 for holding the contacts on the carrier bar and after the carrier bar has been positioned in the axially extending slot 26, the contacts Will be firmly retained in the block by the carrier. It will be apparent that the principles of the invention can be used in a wide variety of multicontact connectors other than the specific type shown. For example, the contact receiving cavities might extend inwardly from only the underside 32 of the block and the contacts could then be of the type which are adapted to be used for the printed circuit edge connectors. The contacts could also have further contact portions extending through the opposite side 36 of the block.

Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is oifered by way of illustration only.

What is claimed is:

1. An electrical connector comprising an insulating housing having an axially extending slot on one side thereof, a plurality of transverse slots extending inwardly on said one side and on a side adjacent to said one side and intersecting said axially extending slot, said transverse slots constituting contact-receiving cavities, and a retaining member of insulating material having a force fit in said axially extending slot whereby, upon mounting contacts on said retaining member and fitting said retaining member in said axially extending slot, said contacts are inserted into said cavities and are retained in said cavities by said retaining member.

2. A device as set forth in claim 1 wherein said insulating block is of a substantially firm, rigid insulating material and said retaining means comprises an elongated strip of relatively softer insulating material.

3. A device as set forth in claim 1 wherein said contacts have contact portions extending at right angles to each other, one of said contact portions extending beyond said one side of said block and another of said contact portions extending beyond said adjacent side.

4. An electrical connector comprising an insulating housing having an axially extending slot on one side thereof, a plurality of spaced-apart contact-receiving cavities extending transversely of the axis of said block and extending inwardly from said one side and from a side adjacent to said one side, said cavities intersecting said slot and a retaining member having a force fit in said slot whereby, upon mounting a plurality of contacts on said retaining member with said contacts in straddling relationship to said retaining member and fitting said retaining member in said slot, said contacts are inserted into said cavities and are retained in said cavities by said retaining member.

5. A device as set forth in claim 4 wherein said block is of a relatively firm rigid insulating material and said retaining member is of a relatively soft compressible insulating material whereby said retaining member is retained in said slot by virtue of internal compression.

References Cited UNITED STATES PATENTS 2,520,970 9/1950' Shields 33991 3,026,494 3/1962 Andersen et a1 33917 3,086,190 4/1963 Neidecker et al. 339177 3,149,897 9/1964 Martineck 339l76 3,184,699 5/1965 Spera 339221 XR 3,208,026 9/1965 Ruehlemann 33917 3,264,597 8/1966 Gammel 339196 XR MARVIN A. CHAMPION, Primary Examiner.

P. A. CLIFFORD, Assistant Examiner. 

